Methane Hydrate Behavior for Water–Oil Systems Containing CTAB and Synperonic PE/F127 Surfactants

Methane hydrates were studied in systems containing aqueous dissolved surfactants in oil emulsions with a volume ratio of 40/60. Two commercial surfactants, named synperonic PE/F127 and cetyltrimethylammonium bromide, were evaluated at 0, 350, 700 and 1500 ppm. Experiments were made by applying the cooling–heating path in an isochoric high-pressure cell at different initial pressures of 5.5, 8.0, 10.0 and 12.0 MPa. The obtained parameters were induction time, temperature onset, pressure drop, and dissociation conditions. The results revealed that the dissociation curve for methane in water-in-oil emulsions was not modified by the surfactants. The crystallization (onset) temperature was higher using synperonic PE/F127 in comparison with zero composition, while the opposite occurred with cetyltrimethylammonium bromide. Both surfactants induced a delaying effect on the induction time and a lesser pressure drop.